Rails 4.2 OmniAuth Koala Facebook phase2

We have a rails 4.2 app running on AWS Elastic Beanstalk, using delayed_job OmniAuth and Koala to interact with Facebook. The app also offers multiple identities per user account (Facebook, Twitter, Email) When user posts on the app, there's a "post to facebook" checkbox. If checked, it posts to user's wall. The app requests "publish_actions" and "user_location" up-front to allow this posting and to customize a geographic filter. This works today. Looking for engineer to provide source code change to make enhancements to the application without breaking other parts of the app (e.g., non-Facebook login). Here are the enhancements for phase 2: A. Selective permissions The desired behavior is to only request additional permissions (e.g., "publish_actions") when the user tries to use the functionality (e.g., post to facebook). Would like to parallel, allowing other request (e.g., posting as page, user_location) to be shifted from up-front to when user wants to use specific functionality. B. Act as Page: Want to allow Facebook user who is admin of a Facebook page to act as their page in the app (e.g., like, post content, ). C. Change password problem: If a user authorizes the app, and then changes their Facebook password, the app does not allow the user to login. Need to fix this problem D. Deauthorize callback URL for facebook app E. Having some problems making canvas app function properly without opening security holes. Also want to allow deep linking into the canvas app. I will provide source code, but not direct server access. If any configuration changes are required, you will provide instruction and we will implement. Project needs to completed within one week of acceptance, and requires NDA.